Oldenburg Land is a region and regional association in the German state of Lower Saxony in the area of the former Grand Duchy of Oldenburg (1815–1918), the later Free State of Oldenburg (1918–1946) and administrative district of Oldenburg (1946 to 1978), without its exclaves, along the rivers Hunte and Hase. In the region between coastline, Dümmer and Damme Hills some of the population still speak Low German today and, in Saterland also Saterland Frisian. The region is rich in old Lower Saxon customs such as Schützenfests or Kohlfahrten. Typical country sports include Klootschießen and Boßeln.

The mainly Catholic southern part of the Oldenburg Land is known as Oldenburg Münsterland, the mainly Lutheran northern part is known as Oldenburg Land (Old Oldenburg) in its narrower sense.

In terms of Germany's modern administrative districts, Oldenburg Land roughly corresponds to Ammerland, Cloppenburg, Delmenhorst, Friesland, Oldenburg (rural), Oldenburg (urban), Vechta, Wesermarsch, and Wilhelmshaven. These 9 districts have a combined population of about 1.1 million (per the end of 2016) and an area of about 5,700 km2 (2,200 mi2).

The borders of the Oldenburg Land are still clear today from the boundaries of institutions such the Evangelical Lutheran Church in Oldenburg, the Offizialatsbezirk Vechta of the Roman Catholic Diocese of Münster and the Landessparkasse zu Oldenburg.